I appear to have a small issue with circles on a reprap mendel - the start/stop position when the hot end moves to the next loop of a print has a definite ‘kink’ in it (so the hot end finishes a circle in a slightly different place to where it started the circle).
I’d be grateful for any suggestions as to what is happening here - is it a hardware / software / calibration issue?
Just guessing, but could it be thermal…if the start as cooled/contracted before head gets all the way round?
Backlash most likely. Check your pulleys and belts, make sure they’re tight and not slipping. Also make sure your motor is not missing steps.
In addition to what @Stephanie_A suggested, make sure your pulleys aren’t slipping.
Make sure your belt tension doesn’t change during movements from end to end and that your belts are perfectly parallel to your axis travel.
It may sound silly but as my printer hotend/extruder warmed up the j-head got very slightly loose. Maybe worth a look. And also try cooling the stepper drivers.
Thanks for the tips, it does seem to be a mechanical thing, I’ll check the X/Y belt tension and position. It’s strange that it only appears to be an issue with circle shapes, and quite regular.
